RATIONALE
Inhaled long-acting beta-agonists (LABAs), when used as monotherapy in asthma, may increase asthma-related hospitalizations, life threatening events requiring intubation/mechanical ventilation, and asthma-related deaths, but concomitant use of inhaled corticosteroids (ICS) may modify this effect.
OBJECTIVES
To determine the safety of long-acting beta-agonists among patients with asthma using corticosteroids.
METHODS
We conducted a systematic review and metaanalysis of parallel-group, blinded, randomized, controlled trials with at least 12 weeks of treatment addressing the impact of LABA on asthma-related and total morbidity and mortality in patients concomitantly using ICS. We searched MEDLINE, EMBASE, ACPJC, and Cochrane (Central) databases, and contacted authors and sponsors.
MEASUREMENTS AND MAIN RESULTS
We used a random effects model to pool results from different studies as odds ratios (ORs) (95% confidence interval [CI]) (OR < 1.0 favors LABA). The search yielded 62 relevant studies included in this analysis. Among over 29,000 participants (15,710 taking LABA, with over 8,000 patient-years observed in the LABA groups), there were three asthma-related deaths and two asthma-related, nonfatal intubations (all in LABA groups; <or= one event per study). Differences in asthma-related hospitalizations (OR, 0.74; 95% CI, 0.53-1.03) and asthma-related serious adverse events (mostly hospitalizations; OR, 0.75; 95% CI, 0.54-1.03) failed to reach statistical significance. The OR for total mortality was 1.26 (95% CI, 0.58-2.74), reflecting 14 deaths in LABA groups and eight deaths in control groups, respectively.
CONCLUSIONS
In patients with asthma using ICS, LABA did not increase the risk of asthma-related hospitalizations. There were very few asthma-related deaths and intubations, and events were too infrequent to establish LABA's relative effect on these outcomes.